LANSING, Mich. — State cutbacks have left many of Michigan's prison towers unmanned as improved technology and shrinking budgets make them as obsolete.

The Mound Correctional Facility and Ryan Correctional Facility, both in Detroit, became the last of the state’s 34 prisons this past summer to end around-the-clock tower guard duty. While armed officers watch prisoners move around the facilities, the towers are no longer the prisons’ main line of defense against escapes, according to a Michigan Department of Corrections official.

Implemented over the past two years to save money, the move to rely more on high-tech surveillance follows a national trend as cash-strapped states look for ways to cut costs.

By placing video cameras on prison fences, one officer behind a bank of monitors can do the work of numerous tower guards.